Quantitative Plant Biology

Growth kinematics and soil mechanics are key to explain how roots overcome the mechanical resistance of soil, yet few studies are linking these two factors. Formulas for cone penetration tests are typically used to infer the friction experienced by roots, but these fail to consider how growth affects the external forces applied on the root. This study formalised how expansive growth in the root apical meristem can reduce soil friction, and applied the framework to analyse the growth strategy of 6 plant species. The results of the analysis revealed trade-offs between reducing frictions, maintaining a desired growth trajectory and elongation rate. A shorter elongation zone can reduce the fraction of the mechanical energy lost to friction, but this is done at the expense of the elongation rate. A sharper tip or increased radius can help roots maintain the elongation rate at no energetic cost, but these strategies come with the cost of growth instability (tortuous roots) and decrease in specific root length respectively. During establishment, root strategies may therefore occupy a 2-dimensional trait space in which the mechanical efficiency of growth is balanced against the explorative-exploitative trade-off. HighlightsGrowth and form of root tips explain how plants overcome mechanical resistance from the soil Trade-offs link the energy lost by friction, growth stability and elongation rate of roots Larger roots allow faster growth independently of these trade-offs New framework formalises plants strategies to acquire soil resources

The sizes and shapes of organs are established by the combined actions of cell proliferation and cell growth. In plants, development of the determinate planar leaf is initiated by primordia formation and establishment of abaxial/adaxial polarity [1,2,3]. Lamina outgrowth is driven by cell division and growth along proximo-distal (PD) and medio-lateral (ML) axes [4], established by mutually repressive PD gradients of miRNA and target transcription factors [5,6,7,8]. These gradients generate proximal regions of competence for cell division and increased growth, with distal regions of reduced growth, endoreduplication and differentiation. The transition from proliferation to growth and differentiation is marked by a cell cycle arrest front, which moves basipetally during leaf growth, progressively restricting proximal proliferative zones as the leaf grows [9,10,11]. Intersection of proximal proliferation-promoting gradients with distal differentiation-promoting gradients may delineate the arrest front, but its dynamics remain poorly understood. We reasoned that mutants affecting cell proliferation patterns may provide insights into the formation, maintenance and dissolution of the arrest front. Spatio-temporal modelling of live imaging data of loss of function mutants of the regulatory peptidase DA1 and its E3 ligase activator Big Brother (BB), which increase cell proliferation [12,13], showed that these proteins effectively establish a threshold cell size at division as a function of distance from the base of the growing leaf and the duration of growth. Loss of BB and DA1 activities increased the persistence of cell divisions and dissolved the arrest front. This suggested that the arrest front emerges from the interactions of threshold areas of cell division with the cessation of division over time, and not from an independently-specified boundary.

Whole genome duplication is a common mutation in eukaryotes with far-reaching phenotypic effects. The resulting morphological, physiological, and fitness consequences and how they affect the survival probability of newly polyploid lineages are intensively studied, but very little is known about the effect of genome doubling on the short-term evolvability of populations. Understanding the effect of polyploidization on the adaptive potential of populations is of crucial importance to predict the future of polyploid populations. In this paper, I investigate the immediate consequences of genome doubling on the genetic variance of populations. To do so, I performed numerical iterations and simulations of how the genetic variance of a quantitative trait changes after polyploidization, under different genetic architectures (additivity, dominance, and epistasis). I found that genetic variance generally decreases after genome doubling. Non-additive gene actions can make autotetraploid populations genetically more diverse than their diploid progenitors in rare cases, notably with overdominance and directional epistasis. By collecting estimates from the agronomic literature, I found that both dominance and epistatic variance contribute to the genetic variance of polyploid populations. These results bring new insights into the adaptive potential of newly formed tetraploid populations, and call for further experimental investigations of how polyploidization is associated with a short-term decrease in evolvability.

(1) RationaleQuantifying and predicting plant morphology is central to understanding development and evolution, yet many plant forms lack homologous features required for traditional morphometrics. We apply the Euler Characteristic Transform (ECT), an injective descriptor from topological data analysis, to encode 2D plant shapes. The ECT converts contours into image-like representations that preserve shape information while enabling deep learning. (2) MethodsWe computed ECTs for large datasets of leaf and pavement cell shapes and used convolutional neural networks (CNNs) for classification. We also trained CNNs to approximate the inverse mapping, predicting leaf shape masks from radial ECTs. (3) Key resultsECT-based models achieved high classification accuracy, surpassing previous approaches on millions of herbarium-derived leaves. Notably, grapevine leaf venation was predicted from blade geometry alone, demonstrating that vascular structure is encoded in the outline. (4) Main conclusionThe ECT provides a compact, information-preserving representation of biological shape that integrates naturally with deep learning. It enables both accurate classification and predictive reconstruction, revealing latent morphological information and offering new opportunities to study plant form across scales.

O_LIIn fluctuating environments, the kinetics of stomatal opening and closing influence the balance between carbon gain and water loss. Smaller guard cells may respond faster to fluctuating environmental conditions because of their greater surface area for osmolyte flux relative to cell volume. A related hypothesis is that operational stomatal conductance (gop) is often well below its theoretical maximum (gmax) because at this stomatal aperture, guard cell volume is poised to change rapidly with small changes in turgor pressure. C_LIO_LIWe analyzed 2,124 estimates of stomatal closure kinetics in response to an abrupt increase in vapor pressure deficit (VPD) among 29 diverse wild tomato populations in the genus Solanum. C_LIO_LILeaves with small guard cells and a lower gop to gmax ratio (fgmax) closed faster, but explained variation in kinetic parameters at different levels of biological organization. Guard cell size had high phylogenetic heritability and varied relatively little within populations, whereas fgmax varied mostly among individuals and between light intensity treatments. C_LIO_LISmaller stomata can be speedier, but only if stomata are held at an aperture where they are responsive to changing turgor pressure. Selection on stomatal speed may influence not only anatomical traits like guard cell size, but also physiological controls on gop. C_LI

Belowground, plants are exposed to a wide range of biotic stresses that vary in severity and nature, including tissue damage, disruption of vascular connectivity, and depletion of assimilates. How plants adapt their root systems to cope with different types of belowground biotic stresses is not well known. In this paper we compare above- and belowground plant adaptations to three nematode species with distinct tissue migration and feeding behaviours to study mechanisms underlying tolerance to different types of biotic stresses. We monitored both green canopy growth and changes in root system architecture of Arabidopsis inoculated with Pratylenchus penetrans, Heterodera schachtii, and Meloidogyne incognita. This revealed three distinct phases in aboveground plant responses: (i) initial growth inhibition associated with host invasion and tissue damage, (ii) persistent growth reduction associated with nematode sedentarism, and (iii) late growth stimulus in more advanced stages of infection. Specific adaptations in the root systems further revealed fundamentally different stress coping strategies. Tissue damage and intermittent feeding by P. penetrans in the root cortex did not induce significant changes in root system architecture. Tissue damage to the root cortex and prolonged feeding on host vascular cells by H. schachtii induced secondary root formation compensating for primary root growth inhibition. Prolonged feeding on host vascular cell by M. incognita alone did not induce secondary root formation, but was accompanied by typical local tissue swelling instead. Our data suggest that local secondary root formation and tissue swelling are two distinct compensatory mechanisms underlying tolerance to sedentarism by root-feeding nematodes. HighlightHow plants utilize root system plasticity to cope with different types of biotic stresses by root feeding nematodes remains largely unknown. Here, we report on specific adaptive growth responses in Arabidopsis roots to three nematode species, Pratylenchus penetrans, Heterodera schachtii, and Meloidogyne incognita, with fundamentally different strategies for host invasion, subsequent migration through host tissue, and feeding on host cells.

Belowground plant trait research has predominantly focused on trade-offs in fine root traits via the root economics space. Yet, this fine root framework captures only a fraction of the functional strategies plants employ beneath the soil surface. Here, we broaden the perspective on belowground plant functioning by integrating traits related to root system extent, clonality and bud banks, using data from the new UNDERPLOT database. This integration links measurable traits to key belowground functions: resource acquisition, spatial exploration, and persistence. Our analysis shows that the fine root economics space explains less than 5% of the variation in traits related to root system extent, clonality, and bud banks. Instead, an expanded trait analysis reveals three significant dimensions, explaining 62% of total trait variation. The third dimension, represents an independent, persistence-related gradient, not captured by existing root economics frameworks. We propose that understanding belowground plant strategies requires embracing additional functional gradients. The strategy of persistence, in particular, varies significantly across growth forms and is a critical dimension of plant response to resource limitation and stress, becoming increasingly important as global change shifts disturbance regimes.

BackgroundRAB Guanine Nucleotide Dissociation Inhibitors (RAB GDIs) are important vesicle transport regulators in eukaryotes, participating in the functional cycle of RAB GTPases by stabilizing their non-active GDP-conformation. AimsWe address the importance of the three Arabidopsis thaliana RAB GDI paralogs by genetic and developmental analyses and put these results into the seed plants evolution context. MethodsWe use methods of genetics, microscopy and phylogenetics. ResultsOur genetic analyses of Arabidopsis T-DNA insertional mutants confirm recent CRISPR alleles data indicating lethality of double gdi1 gdi2 mutants, and our microscopic data point to embryo development arrest in double mutant seeds. We also confirm the involvement of GDI2 and GDI3 in pollen tube growth. Moreover, our data show that GDI1 also contributes to proper pollen function. Our phylogenetic analysis reveals independent diversification of RAB GDIs in Gymnosperms and Angiosperms, with early specialization of an Angiosperm reproduction-and gametophyte-related clade. ConclusionsIn Arabidopsis, RAB GDI1 and 2 are important for the vegetative growth while RAB GDI2 and 3 are vital for reproduction. Evolution of the RAB GDI family reflects the evolution of seed plants. HighlightsRAB GDIs are vital for plant growth and reproduction and act redundantly. Even the low-transcribed RAB GDI1 isoform contributes to the proper pollen function. Two RAB GDI clades evolved in early Angiosperms.

The source{square}sink attenuation hypothesis suggests that plants regulate carbon fixation in response to fluctuations in sink demands. Many evergreen trees exhibit flushing growth patterns, where new shoot development generates a strong, transient demand for both carbon and nitrogen that may influence the function of mature leaves. This study examined the source-sink attenuation hypothesis in the context of vegetative sink growth by investigating the photosynthetic capacity and nitrogen dynamics in mature citrus leaves across three stages of flush development. In contrast to expectations, photosynthesis declined as flush growth progressed. Early flush initiation induced stomatal limitation in mature leaves, whereas as sink demand from further shoot growth continued carboxylation capacity and Rubisco abundance declined, despite relatively stable total leaf nitrogen. These results suggest that mature leaves undergo selective protein retooling under prolonged sink demand, constraining CO{square} fixation while maintaining C export. Overall, this study revealed that under strong combined N and C sink demands, mature citrus leaves function primarily as regulated carbon conduits rather than dynamically upregulating photosynthesis, providing new insight into source-sink coordination in woody perennial species. HighlightCitrus flush growth shows that mature leaves suppress photosynthesis through stomatal and biochemical regulation while reallocating carbon and nitrogen to support new shoot development, challenging classic source-sink theory.

Efficient gas and water exchange between plants and their environment largely depends on the number and distribution of stomata, cellular valves in leaf epidermis. Core genetic regulators of stomatal cell identity and pattern along with asymmetric stem-cell like divisions in stomatal precursors are hypothesized to customize stomatal production for optimal leaf performance. How these regulators work in concert and how division dynamics are modified and adjusted in different environments, however, are poorly understood. Here, we leveraged the variation in stomatal patterning in Arabidopsis thaliana accessions from diverse environments to define developmental rules and constraints in the stomatal lineage. The accessions subtle and quantitative variation enables us to identify which cellular parameters are flexible, revealing how developmental plasticity generates phenotypic plasticity. By developing live-cell imaging tools to track cellular behaviors during leaf growth under varying environmental conditions in these accessions, we could decompose stomatal density variation into its developmental origins. Variation in final stomatal numbers is driven by differences in the relative contributions of stomatal initiation, cell size-based fate thresholds, general proliferative capacity, and coordination between sister and neighbor cell behaviors. Overall, diverse accessions converge toward two lineage regimes: one dominated by autonomous decisions with loose cell-cell coordination, the other by extensive cell-cell coordination. Challenging accessions with environmental fluctuations revealed regime-specific flexibility, with plasticity primarily mediated by a single division-related parameter. Our results show how cellular parameters integrate into alternative developmental strategies that shape environmental responsiveness.

While most plant lineages are pigmented by anthocyanins, several families in the Caryophyllales represent a major exception by showing a replacement of anthocyanin pigmentation by betalain pigmentation. The mutual exclusion of anthocyanins and betalains at the family level has been well established for over 50 years and has been mechanistically explained. Chenopodiaceae are a betalain-pigmented lineage lacking a key anthocyanin biosynthesis gene and lacking the key activating transcription factor of the anthocyanin biosynthesis. A publication by Zhang et al., 2024 claims that anthocyanins would be responsible for the red pigmentation in leaves of Chenopodium quinoa. Here, we assessed this study and reanalyzed the RNA-seq datasets generated in this study to demonstrate that there is no evidence for anthocyanin biosynthesis, but activity of the betalain and carotenoid biosynthesis could explain the observed pigmentation of quinoa leaves.

In developing tissues, cells differentiate into distinct cell types and form complex spatial patterns. How distinct patterning systems interact during tissue growth to shape tissue composition and spatial organization remains poorly understood. Here, we investigate this question in the abaxial leaf epidermis of Arabidopsis thaliana, in which the same pool of progenitor cells gives rise to stomata, pavement cells, and giant cells. Using a quantitative approach combining Euclidean and network-based spatial analysis, we show that stomatal number and density are robust to reduced endoreduplication, whereas forced endoreduplication actively competes with the stomatal lineage to reduce stomatal number. Furthermore, we show that the stomatal spatial pattern is also shaped by the broader tissue context such as cell growth, cell division, and giant cell patterning, with distinct consequences for stomatal spatial distribution and cellular arrangement. Our results highlight that the interplay between patterning systems must be considered to understand how tissue organization is established.

O_LIPhotoperiod is a stable seasonal signal. Although the photoperiodic flowering is well understood in short-day (SD) and long-day (LD) annual plants, regulatory mechanisms in perennials remain elusive. In a perennial woodland strawberry (Fragaria vesca L.), flowering is induced in SDs in autumn and plants flower following spring, while in plants with mutated FvTERMINAL FLOWER1 (FvTFL1), LDs induce flowering. C_LIO_LIWe investigated photoperiodic flowering of F. vesca through phenotypic and molecular characterization of transgenic lines and their crosses. We studied natural variation in flowering time and gene expression in European accessions, and explored their correlations with climatic, geographical and genetic origins. C_LIO_LIWe showed that FvGIGANTEA (FvGI) and FvCONSTANS (FvCO) activate FvFLOWERING LOCUS T1 (FvFT1) in LDs resulting in early flowering in fvtfl1 mutant, while in SD F. vesca, activation of FvTFL1 by FvFT1 reverses the photoperiodic requirement of flowering. In natural accessions, decreasing expression of FvFT1 and FvTFL1 towards colder climates in the east and north correlated with earlier flowering. C_LIO_LIWe define a photoperiodic flowering mechanism controlling floral transition of perennial F. vesca in autumn that differs from known mechanisms in annual and perennial plants. Our findings open new avenues to understand how perennial plants cope with changing seasons across climatic and geographical ranges. C_LI

O_LIResearch and rationale: This study investigates whether tissue-specific ethylene biosynthesis regulates stomatal conductance (gs) responses to changing [CO2] in Arabidopsis thaliana. While guard cells sense [CO2], mesophyll-derived signals are also implicated in stomatal control. We aimed to determine if ethylene production in guardcells or mesophyll is the primary driver of CO2-induced gs regulation. C_LIO_LIMethods: An acs octuple mutant with severely reduced ethylene production was complemented with tissue-specific ACS8/ACS11 transgenes driven by guard-cell, spongy-mesophyll, dual palisade/spongy-mesophyll, or whole-leaf promoters. Tissue-specific complementation in the different transgenic lines was confirmed and evaluated by qPCR, tissue-specific NEON expression, microscopic imaging, and ethylene production measurements. Gas-exchange measurements on intact plants recorded gs kinetics, CO2 assimilation, and water-use efficiency, across CO2 shifts. C_LIO_LIKey results: Guard-cell complementation nearly fully restored wild-type gs responses and reversed the mutants aberrant leaf phenotype. Spongy-mesophyll complementation failed to rescue either trait, while dual palisade- and spongy-mesophyll complementation yielded only partial recovery. C_LIO_LIConclusion: Ethylene produced in guard cells is the dominant regulator of CO2-induced stomatal conductance regulation, with mesophyll-derived ethylene contributing secondarily via long-distance signaling or by augmenting the overall ethylene pool. These findings underscore the importance of spatially regulated ethylene biosynthesis in balancing carbon assimilation and transpiration. C_LI

Mathematical modelling is essential for understanding how complex biological systems respond to genetic, physiological, and environmental changes. Existing approaches, however, often require trade-offs between mechanistic detail, model size, parameter uncertainty, and interpretability. Ordinary differential equation (ODE) models capture biochemical processes with quantitative precision but can demand extensive parameterisation. In contrast, large statistical and machine-learning models rely on substantial datasets and frequently lack mechanistic transparency. Qualitative approaches such as Boolean networks improve scalability but may oversimplify biological behaviour. To address some of these limitations, we present PSoup, an R package that automatically converts knowledge graphs into transparent, parameter-free, qualitative models. PSoup uses algebraic update rules designed around a fixed, biologically interpretable baseline, enabling predictions of relative change across diverse perturbations without requiring kinetic parameters. This design allows PSoup to integrate information across biological scales and from heterogeneous experimental sources. We evaluated PSoup using the well-studied shoot branching network of Bertheloot et al. (2019), which ncorporates hormonal (auxin, strigolactone, cytokinin) and metabolic (sucrose) regulation. Across 78 experimental conditions, PSoup correctly predicted 88.5% of perturbation outcomes, including 89.5% accuracy for unique, biologically consistent comparisons. We further demonstrate how PSoup can distinguish among alternative plausible network topologies, revealing how structural differences influence emergent system behaviour. PSoup offers an intuitive, accessible, and mathematically transparent framework for exploring biological networks. Its capacity to integrate diverse knowledge and test alternative hypotheses positions it as a powerful tool for biological discovery and a valuable complement to existing modelling approaches.

Amphibious plants can thrive in both terrestrial and submerged environments, which are fundamentally distinct. Although morphological plasticity of leaf known as heterophylly has been well investigated, the morphological plasticity of root in amphibious plants remains poorly understood. In this study, we discovered that an amphibious plant Callitriche palustris (Plantaginaceae), which has significant heterophylly, has a remarkable morphological plasticity also in root in response to submergence. This species develops thin roots with abundant root hairs, fewer cortical and epidermal cells, and smaller aerenchyma in the terrestrial condition. On the other hand, it develops thicker roots with few root hairs, more cortical and epidermal cells, and larger aerenchyma in the submerged condition. We call this morphological plasticity of root as "heterorhizy". Phytohormone perturbation experiments revealed that abscisic acid (ABA) and gibberellin regulate root hair development and root cell division respectively. We also found the possibility that heterorhizy was acquired in the genus Callitriche. Additionally, a similar form of root hair plasticity was also observed in the phylogenetically distinct amphibious species Ludwigia arcuata (Onagraceae). Furthermore, the absence of root hair development underwater and the similar structure of aerenchyma to C. palustris were broadly seen across diverse aquatic plants. This study provides new insights into the root morphological responses to submerged environments in aquatic plants.

PremiseHerbarium specimens are increasingly used to extract morphological traits for ecological and evolutionary studies, yet the effects of tissue desiccation on trait measurements remain poorly understood. Here, we tested whether higher tissue water content leads to greater measurement changes after herborization (H1) and whether fresh trait values can be reliably predicted from herbarium measurements (H2). MethodsWe evaluated the reliability of herbarium-based measurements by comparing fresh and dried traits of leaves, flowers, fleshy fruits, and seeds across 262 individuals representing 133 Neotropical Myrtaceae species. Phylogenetic least square models and machine-learning regressions were used to test H1 and H2. ResultsLeaves and flowers generally shrank after herborization, fruits size metrics tended to increase, and seeds were largely unaffected. Water content was significantly associated with the magnitude of herborization effects in flowers and some leaf and seed traits. Fresh trait values were accurately predicted from herbarium measurements. Prediction errors were lowest for leaf traits, followed by fruits, flowers, and seeds. DiscussionThese results partially support H1 and support H2, indicating that herbarium specimens can be reliably used for trait analyses when organ-specific responses are considered, providing a practical framework to account for potential desiccation bias in functional trait research.

In plant cytokinesis, the partitioning membrane is made by homotypic fusion of secretory vesicles, progressing in a centre-to-periphery direction. In Arabidopsis, this process is mediated by a cytokinesis-specific fusion machinery involving Qa-SNARE KNOLLE which is made during G2/M phase and degraded at the end of cytokinesis. Here we analyse how the turnover of KNOLLE protein is regulated. KNOLLE is ubiquitinated, which is best detected after combined treatment with inhibitors of endocytosis and de-ubiquitination. Site-directed mutagenesis of three clustered lysine residues prevented ubiquitination and internalisation, resulting in stable accumulation of KNOLLE at the plasma membrane in all cells of the seedling root. This is in stark contrast to the transient accumulation of wild-type KNOLLE in dividing cells only. Partial-substitution mutant lines revealed redundancy of lysine residues in both KNOLLE ubiquitination and turnover. KNOLLE ubiquitination resulted in K63-linked ubiquitin chains known to be involved in endocytosis whereas K48-linked chains were not detected. To explore the spatio-temporal conditions, we analysed KNOLLE ubiquitination in cis-SNARE and trans-SNARE complexes during membrane traffic and cell-plate formation. Our findings suggest that KNOLLE protein turnover is caused by a ubiquitination process that depends on successful membrane fusion generating the cell plate.

Plants acclimate to mechanical stimuli such as touch and wind via thigmomorphogenesis, a suite of developmental responses that alter their growth and architecture. However, the early signaling mechanisms translating mechanoperception into long-term morphological changes remain incompletely understood. We investigated the role of the rapidly touch-induced transcription factor RRTF1 (REDOX RESPONSIVE TRANSCRIPTION FACTOR 1) in these processes. Phenotypically, under aggressive mechanical stimulation, rrtf1 mutant exhibited attenuated stunting (less height reduction). This suggests a key role for RRTF1 in promoting thigmomorphogenic responses under severe mechanical stimuli, though the rrtf1 mutant responded similarly to wild-type under gentle, repeated brushing. The alleviation of growth stunting in rrtf1 was largely jasmonic acid (JA)-independent. Transcriptome analysis at 10 minutes post-touch revealed that rrtf1 mutant maintained approximately 86% of wild-type touch-responsive gene expression. Nevertheless, RRTF1 modulated specific regulons, partly through an interplay with WRKY transcription factors, as evidenced by altered TF binding motif enrichment in RRTF1-specific differentially expressed genes. We conclude that RRTF1 acts as a modulator of early touch signaling in Arabidopsis shoots. It is not essential for the bulk of the initial transcriptional response but fine-tunes specific gene sets and plays a crucial role in calibrating long-term thigmomorphogenic development, particularly by promoting growth inhibition under severe mechanical stimulation. This study provides insights into the alleviation of touch-induced growth inhibition in rrft1 mutant, which might be relevant to breeding for crops that are planted in high density and experience constant physical contact with neighboring plants.

The genetics of interspecific groups remains largely unexplored, despite the central role of social (or indirect) genetic effects in shaping phenotypic expression within communities. Intercropping, i.e. the simultaneous cultivation of multiple crop species in the same field, offers a powerful model to harness these interspecific social effects. Such species mixtures provide well-documented agricultural benefits, yet few breeding frameworks have integrated the genetics of social interactions. Here, we address this gap by extending quantitative genetic theory to interspecific groups, with intercropping as a concrete and applied model case. We propose a quantitative genetic model that jointly analyzes intra and interspecific interactions within a unifying framework. Breeding values are decomposed into a direct component, shared in mono and mixed-crops, an interspecific social component corresponding to the effect of one species on another, and an intraspecific component that captures the social effects within a mono-genotypic stand of cloned plants. Statistically, this consists in simultaneously fitting several linear mixed models, one per stand type, all having direct breeding values in common. As no open-source software can fit such a complex mixed model, we provide such an implementation in R/C++. Simulations across various genetic (co)variance structures and sparse experimental designs showed accurate estimation of all genetic (co)variances and breeding values. With an incomplete, yet balanced design combining sole crops and intercrops, genetic gains in both systems were achievable simultaneously, enabling breeding strategies that progressively integrate intercropping into existing, sole-crop-only schemes. More broadly, this framework allows dissecting direct and social genetic effects when genotypes are observed in mono- and mixed-species situations, cultivated or not.